Phase 3 Trial of Libtayo® (cemiplimab) Monotherapy in Advanced Cervical Cancer Stopped Early for Positive Result on Overall Survival

News // Press Releases
March 15, 2021

Libtayo is the first immunotherapy to demonstrate improved overall survival in patients with cervical cancer, reducing the risk of death by 31% compared to chemotherapy

Trial enrolled patients with advanced cervical cancer regardless of PD-L1 status

Fourth cancer type where Libtayo has positive pivotal data; first-in-class survival results in cervical cancer follow first-in-class pivotal results in advanced BCC and advanced CSCC

Regulatory submissions planned in 2021

Tarrytown, N.Y. and Paris March 15, 2021 – Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) and Sanofi today announced positive results demonstrating an overall survival (OS) benefit from the Phase 3 trial investigating the PD-1 inhibitor Libtayo® (cemiplimab) monotherapy compared to chemotherapy, in patients previously treated with chemotherapy whose cervical cancer is recurrent or metastatic. The trial will be stopped early based on a unanimous recommendation by the Independent Data Monitoring Committee (IDMC), and the data will form the basis of regulatory submissions in 2021.

“Libtayo monotherapy is the first medicine to demonstrate an improvement in overall survival in women with recurrent or metastatic cervical cancer following progression on platinum-based chemotherapy in a Phase 3 trial,” said Krishnansu S. Tewari, M.D., Professor and Director of the Division of Gynecologic Oncology at the University of California, Irvine and a trial investigator. “This landmark clinical achievement will bring hope to women with advanced cervical cancer who are often younger than patients with other cancers. This is reflected in this trial where the average age was 51.”

This is the largest Phase 3 randomized clinical trial in advanced cervical cancer, and included women (median age: 51 years) with either squamous cell carcinoma or adenocarcinoma. Patients were randomized to receive Libtayo monotherapy (350 mg every 3 weeks) or an investigator’s choice of commonly used chemotherapy (pemetrexed, vinorelbine, topotecan, irinotecan or gemcitabine). Compared to chemotherapy, patients receiving Libtayo experienced:

  • Total population: 31% reduced risk of death
    • Median 12.0 months survival for Libtayo (n=304) compared to 8.5 months for chemotherapy (n=304); hazard ratio (HR): 0.69; 95% confidence interval (CI): 0.56-0.84 (p<0.001)
  • Squamous cell carcinoma: 27% reduced risk of death
    • Median 11.1 months survival for Libtayo (n=239) compared to 8.8 months for chemotherapy (n=238); HR: 0.73; 95% CI: 0.58-0.91 (p=0.003)
  • Adenocarcinoma: 44% reduced risk of death
    • Median 13.3 months survival for Libtayo (n=65) compared to 7.0 months for chemotherapy (n=66); HR: 0.56; 95% CI: 0.36-0.85 (p<0.005; not adjusted for multiplicity)

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